21913836 has 24 divisors (see below), whose sum is σ = 58437120. Its totient is φ = 6261072.

The previous prime is 21913831. The next prime is 21913849. The reversal of 21913836 is 63831912.

It is a junction number, because it is equal to n+sod(n) for n = 21913797 and 21913806.

It is not an unprimeable number, because it can be changed into a prime (21913831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130356 + ... + 130523.

It is an arithmetic number, because the mean of its divisors is an integer number (2434880).

Almost surely, 2^21913836 is an apocalyptic number.

It is an amenable number.

21913836 is an abundant number, since it is smaller than the sum of its proper divisors (36523284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21913836 is a wasteful number, since it uses less digits than its factorization.

21913836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260893 (or 260891 counting only the distinct ones).

The product of its digits is 7776, while the sum is 33.

The square root of 21913836 is about 4681.2216354281. The cubic root of 21913836 is about 279.8376439724.

The spelling of 21913836 in words is "twenty-one million, nine hundred thirteen thousand, eight hundred thirty-six".